282 Mr Adam'^s Description and Explaiiation 



to its mouth a part of the tube D 

 m of the filler, and is large enough 

 to contain all the rain water which 

 may thus enter it in the course of 

 twelve hours. 3d, A cylindrical 

 glass tube K L, having its inside 

 diameter about i or fds of an inch, 

 its lower extremity, L, hermetical- 

 ly closed, its upper extremity, K ^, 

 funnel-shaped, so that the rain wa- 

 ter to be measured may be easily 

 poured into it from the bottle; 

 and one of its sides accurately gra- 

 duated, from L to K, into portions 

 having the capacity of cubic inches, 

 and tenths, &c., of a cubic inch. 

 4th, A post D I, fixed vertically 

 in a sheltered situation, and hav- 

 ing, 1^^, a horizontal shelf H G 

 perpendicular to it, about 2 or 3 

 feet above ground, to support the 

 bottle; 9>d, A bent iron hoop cde, fixed to post at c and e, so 

 as to hold the bottle firmly in its place when exposed to storm ; 

 and, Srf, Two strong wire hold fasts, fg, h i, screwed into the 

 post at g, and i, and formed so as conveniently to hold the 

 graduated glass measure K L, that it may be always ready to 

 ascertain the number of cubic inches, and tenths, and hundredths 

 of a cubic inch, of the rain water which has entered the bottle, 

 and consequently also the depth of rain which has fallen in the 

 adjacent country in hundredth, thousandth, and ten thousandth 

 parts of an inch. 



Explanation. — The superficial area of the mouth of the filler 

 being 100 square inches, it is obvious that 100 cubic inches of rain 

 water must pass through it into the bottle, when 1 inch deep of 

 rain falls in the adjacent country ; that every cubic inch of this wa- 

 ter, being the hundredth part of the whole, must indicate the hun- 

 dredth part of an inch deep of rain; and that every tenth and 

 hundredth part of a cubic inch of such water, measured in the 

 graduated glass tube K L, must likewise indicate the thousandth 



